In the discussion of the background that follows, reference is made to certain structures and/or methods. However, the following references should not be construed as an admission that these structures and/or methods constitute prior art. Applicant expressly reserves the right to demonstrate that such structures and/or methods do not qualify as prior art.
Externally retained tool picks, such as mining and trenching picks, are conventional for the mechanical excavation of rocks and minerals. Such tool picks include a head, which contacts rocks and minerals during excavation, and a shank, which is mounted in a holder. A retainer, which can come in several forms, is positioned about the shank of the tool pick and retains the tool pick in the holder while also allowing rotation of the tool pick. Typically, the retainer uses spring-like behavior to allow the retainer to be placed over and retained about the shank.
Tool picks mounted in blocks can have a shank that protrudes from an end of a mounting bore. The shank can have a recess, such as a groove, which receives a retaining element. The retaining element is conventionally a spring steel having a C-shape, and is held in place in the recess by spring forces. The radial size of the retaining clip positions sides of the retaining clip in contact with the surface of the block to prevent the tool pick from being removed from the block.
To install retaining clips, such as a c-clip, a force is required to press the retaining clip into the groove. When the retaining clip is pressed into the groove, the ends will bend outwardly from each other so as to enable the retaining clip to snap into place. When the retaining clip is properly installed on the shank, an inner surface of the curved portion bears upon the groove to prevent further transverse movement of the retaining clip relative to the shank. To remove the clip, a force can be applied to the ends of the retaining clip to push the retaining clip off the groove.
Retaining clips can be difficult to install and remove from the groove in the shank. This is due, at least in part, to the limited access behind the block, the required spring forces to overcome in order to mount the retaining clip, and the awkwardness associated with positioning and applying a requisite installing and removing force to the retaining clip in an edge-on manner, including in the plane of the retaining element.
A typical tool 10 currently used for installing and removing c-clip style retainers from tool picks is shown in FIGS. 1-3. These tools contain a body including a first end 20 containing two prongs 22. To remove the c-clip 40, the user aligns the end surfaces 24 of the prongs on the tool with portions 42 of the c-clip as shown in FIG. 2, and strikes the opposite end 30 of the tool with a hammer. The square end surfaces 24 on the tool are very difficult to align with the angled end surfaces 42 of a c-clip.
Existing tool designs for installing c-clips employ a smooth cut-away radius 32, an example of which is shown in FIG. 3. The depth of the cut-away radius 32 matches the outside diameter of the c-clip 40, but the radius of curvature of the cut-away 32 fails to correspond to the radius of curvature of the back surface 44 of the c-clip. To assemble the c-clip 40 onto a tool pick 50, the user must align the c-clip 40 on the groove 54 at the rear 52 of the tool pick while simultaneously aligning the radius 32 on the tool with the back surface 44 of the c-clip. Also, the cut-away radius 32 is located near the second end 30 of the tool, and opens in a direction transverse to either end of the tool. Once everything is aligned, the user must carefully strike the side of the tool 10 opposite the cut-away radius 32 with a hammer. Due to the force required, the elastic memory of these retainers, and the alignment difficulties during installation, many are prone to “fly” in any given direction. This can make the installation of the retainers a safety hazard on the job site.
Examples of tools for installing and removing retainers are shown in U.S. Pat. Nos. 5,720,528; 6,428,110; and 7,210,745. However, none of these prior art solutions addressed or improved the tool-to-retainer contact area to improve performance of the tool during removal of the retainer. Also, none of these prior art solutions provide self-alignment of the retainer in the tool during installation of the retainer, to alleviate the difficulty of aligning the retainer in the recessed seating feature during installation.